I am trying to make a decision how to proceed with a small rear main seal leak in my 93 Nissan Sentra. It is an auto with 167,000 k. Purchased with 76,000 miles. Dealership gave free oil changes of Castrol 10w-30 every 3k until this past winter. I have been doing own oil changes with Napa High Mileage 10w-30 since. I saw the oil leaking a few drops between transmission/engine (bell housing?) Front main replaced 45,000 miles ago. One valve cover and two oil pan gaskets replaced. The car is my second car. If the rear main seal needs replacement, I will get rid of the car (lack of money). Out of ignorance, I used Eagle Brand seal conditioner, two times with oil change. It stopped the leak, but as I read on the board, may cause problems down the road. I wrote Frank of Auto-RX. He said it was up to me if I should use Auto-RX. My concern is that some people tend to have more seal leaks when using the Auto-RX treatment, depending on the condition of the seal. I purchased some Maxlife Sythetic 5-30 for Winter a while back. I am confused. I was trying to do something good, but it seems that dino oil would be better for seals. I just purchased a case of Havoline 5W-30. So I could go to straight dino, skip synthetics, or high mileage oil, if it is advisable. Use car about 8,000 a year, mostly highway miles. Want it to last a few more years until I am out of debt. It runs great, is not sludged up, and uses 1/2 quart oil every 3,000 miles. Your recommendations would be appreciated.
Advice needed on slight leak in rear main seal.
- Thread starter MONKEYMAN
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I doubt that the rear main will ever develope into enough of a problem for you to ditch an otherwise perfectly good running car. I've only seen this happen once on a totally null and void 20 year old beater (where the seal was so bad that it "splashed" oil). You have an automatic ...so no fear of soaking the clutch ..
..aside from some drips in the driveway/garage/parking spot (place a floor mat where you park it =plastic outside/ cardboard inside ..replace/clean as needed) ..live with it. This would have to be SEVERE for me to get rid of a car for this reason. I have a friend/mechanic that I get to hang with a few days a month. I have yet to see any vehicle over a few years old without some form of lubricant dripping/seeping somewhere under the car.
Since this appears to be a concern of yours ...I'm with Frank on the A-Rx thing. Some experience increased leakage during the treatment ..but almost all have good results. I did ..but I didn't have a rear main problem (or maybe I did - I never knew where the drips were coming from - they stopped
).
Let me restate this: If the seal leak is as you describe (which I say is, on average, "typical" or not unlikely with a car of your mileage/age) I would have no reservations about using Auto-Rx.
Your oil selection is fine IMHO.
..aside from some drips in the driveway/garage/parking spot (place a floor mat where you park it =plastic outside/ cardboard inside ..replace/clean as needed) ..live with it. This would have to be SEVERE for me to get rid of a car for this reason. I have a friend/mechanic that I get to hang with a few days a month. I have yet to see any vehicle over a few years old without some form of lubricant dripping/seeping somewhere under the car.
Since this appears to be a concern of yours ...I'm with Frank on the A-Rx thing. Some experience increased leakage during the treatment ..but almost all have good results. I did ..but I didn't have a rear main problem (or maybe I did - I never knew where the drips were coming from - they stopped
Let me restate this: If the seal leak is as you describe (which I say is, on average, "typical" or not unlikely with a car of your mileage/age) I would have no reservations about using Auto-Rx.
Your oil selection is fine IMHO.
Gary, my problem is lack of experience. Car knowledge is on an as needed basis. I learn as I go. I guess the transmission shop, that said my transmission would need to be resealed to the tune of $400 back when I bought the car, put the fear of God in me. Did not have it done, and I have never seen the transmission leak, only oil. I am relieved that some oil seeping is normal on the rear main. I have never seen any oil deposited under the car due to this leak. But, after loosing the front main, a common repair on this car, I have more fear. When it went, it was very messy. So, now I am more confident about using Auto-RX, but after posting, I am wondering if just using the Havoline dino would be adequate? Two oil changes a year at 4,000 miles with Havoline? My goal is to spend as little as possible, but still maintain it properly. You never know what will happen when a car is this old. If that slight seal leak is normal, then I don’t know if the expense and time of doing the Auto-RX would be worth it. When you were talking about my oil selection, were you referring to the Havoline? It seems it would be the most seal friendly of the choices.
Just as an odd aside, check your pcv valve, it's a little plastic thing typically on the top of the valve cover. They're only like $3 and they put the inside of the motor at a slight vacuum. If it's clogged pressure builds up and forces oil out the seals faster. Is an often overlooked cheap maintenance part.
eljefino, thanks for the advice. Replaced it less than a year ago before emission testing. On this car, it is metal and screws into the valve cover. The more I think about it, the one drop of oil I see at the bell housing may not be a problem. I have a Saturn that uses twice the oil of my Sentra and has half the mileage. I don't think much of the oil I am using is coming out of the rear seal. It is just this car has leaked like a sieve all over from the day I purchased it! Have a feeling it is the nature of the beast! Now, regarding pressure, I wonder what affect those 75,000 miles of free oil changes affected things. After changing the oil myself, I realized that it was overfilled every time. Capacity is 3.4 quarts. I am sure they put at least 4 quarts in at the Mitsu dealership. Don’t know if that was very good for the seals?
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Yes, uncharted waters are always scary ...even if they're only knee deep (nothing to worry about - if you don't know that ...you worry
I think your oil selection is fine ..as is your OCI. Any alterations that anyone would recommend would require more $$$ invested ..which is something you're trying to avoid. I can see no gainful yield for you under your criteria with either going to synthetics or changing oil brands. Auto Rx is a great product. It's one of the few that I really have faith in ..and that's only due to my own experience with it. That is, there is good to be gained by its use ..but given your needs and lack of any problematic symptoms (lifter tick in spite of good maintenance, smoking due to leaking valve seals, etc.), it's not a "must do".
You're correct. Although they've seemed to extend the life of a car to attain very high mileage, it's kinda like being a senior citzen. You may be in very good health for your age ..but the components are all nearing the end of their service life. Any one failure can scrap the whole unit given the service life expectancy of the rest of the vehicle.
On the other hand ...you've got to have the ability to differentiate your true costs in car ownership. Many, one friend of mine in particular, ditches cars when they start reaching a certain, yet undefined, "nickel and dime" hassle level. I got his 91 Taurus, that needed only a CV joint, for $300 ..the air doesn't work and it needed a water pump (which turned into a discovered slack timing chain)..and I still ended up with less of a "pig in the poke" vehicle for the same amount of money that I would spend on a comparable car (and perfect for my daughter to use while away at college). Many perfectly good cars end up in the junkyard due to automatic transmission failures ....but the same person who didn't want to do a $2000 rebuild (a sinfully over expensive procedure) will then go and spend $3500-7000 on a newer vehicle that may have the same likelyhood of such an expensive failure anytime in the future. They then see the validity of a $2000 repair for a $6000 car (see what I mean
I guess it's always a crap shoot...
As long as the leak is not excessive, don't worry about it. My '90 Sentra had an excessive leak. I got tired of adding a quart every day and leaving an oily slick everywhere I parked. Holes in the oil pan and condo associations suc.k
My '94 never leaked engine oil with 250k miles on all original gaskets/seals. But, I went through a lot of PS fluid until I found one(lucas) that sealed that leak.
Mildly leaking engine seals are no big deal.
I wouldn't worry about the Eagle brand stuff. It seemed to work. Down the road would've required seal replacement anyway.
Stick with the 3k OCI. Quit worrying. Since budget is an issue with a high mileage vehicles, don't bother with the synthetics. But, I like the high mileage oils. They have worked in several vehicles that I service.
Only when adding oil becomes a nuisance should you either junk the car or the seal.
My '94 never leaked engine oil with 250k miles on all original gaskets/seals. But, I went through a lot of PS fluid until I found one(lucas) that sealed that leak.
Mildly leaking engine seals are no big deal.
I wouldn't worry about the Eagle brand stuff. It seemed to work. Down the road would've required seal replacement anyway.
Stick with the 3k OCI. Quit worrying. Since budget is an issue with a high mileage vehicles, don't bother with the synthetics. But, I like the high mileage oils. They have worked in several vehicles that I service.
Only when adding oil becomes a nuisance should you either junk the car or the seal.
For what this is worth, I had a rear main seal leak on my 86 F250 4x4. I think from past experience Lucas is a great stop leak, so it appeared to slow it down, well this year I decided to go to a synthetic oil, so I went to a blend first and as with synthetics leaks appear from nowhere, well now I had oil coming out of the front of the oil pan also. In the middle of the night I had this flash of thought, message in my head said, tighten oil pan bolts. Today I still have a small rear seal leak but less than when I ran dino oil.
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